In addition to more conventional forms of carbon such as graphite and diamond, other forms of carbon include fullerenes, carbon nanotubes (CNTs), and carbon nanofoams. Carbon nanotubes may be understood to refer to an elongated hollow structure having a diameter less than 1 μm. Applicants have produced a tubular carbon structure, herein referred to as “carbon microtubes,” having an average diameter of at least 10 μm, and a wall which has a structure characterized by rectangular voids extending parallel to the central axis of the tube. Applicants have found that this unique structure results in a number of desirable properties which are superior to other forms of carbon, including low density (comparable to that of nanofoams), high strength, excellent ductility, and high conductivity. These properties indicate a potential for a variety of advanced applications. For example, the diameter and the length of carbon microtubes are comparable to cotton fibers, and yet carbon microtubes may be over 200 times stronger than cotton fibers. Therefore, conventional textile technologies may be used to make carbon microtube fabrics suitable for applications such as body armor and other applications requiring lightweight, high strength composite structures.